Audio System

ABSTRACT

An audio system with a loudspeaker configured to create an audio output, a sensor configured to detect at least the presence of at least one person at a position relative to the loudspeaker, and a processor configured to cause the loudspeaker to alter the audio output based on the position of the at least one person relative to the loudspeaker. Altering of the audio output includes adjusting at least one of a volume, a time delay, an equalization, or a radiation pattern of the audio output.

BACKGROUND

This disclosure relates to an audio system.

When there are multiple loudspeakers in a room and a person movesrelative to the loudspeakers, the person's perception of the sound fromthe loudspeakers may change.

SUMMARY

Aspects and examples are directed to an audio system in which the audiooutput of one or more loudspeakers is configured to change based on theposition of a person relative to the loudspeakers. This system can beused to help the listener maintain better immersion in audio frommultiple loudspeakers as the listener moves around the room or otherlocation in which the loudspeakers are located.

In some examples the loudness or volume of a loudspeaker is adjusted tobetter balance sound from multiple loudspeakers. For example, if a usermoves closer to one loudspeaker its gain can be reduced so that thesound from that loudspeaker doesn’t overwhelm the sound from otherloudspeakers.

In some examples a time delay of sound from a loudspeaker is adjusted tobetter balance sound from multiple loudspeakers. For example, delay canincrease as the listener approaches the loudspeaker so that the soundfrom multiple loudspeakers arrives closer to the same time than would bethe case if there was no delay.

In some examples equalization and level are adjusted to compensate forloudspeaker directionality. For example, loudspeakers can become moredirectional at higher frequencies. The frequency response at a givenangle can be compensated by adjusting the output level and equalizationbased on the listener’s angular position relative to the nominal maindirection of sound propagation of the loudspeaker, for example if thelistener is in front of, behind, or off to the side of the loudspeaker.

In some examples the directivity of the main sound lobe of a multipleaudio driver loudspeaker is adjusted based on the listener’s position.For example, a phased array speaker system can generate directionalsound When the listener’s angular position relative to the loudspeakeris known, sound can be directed at the position. Directivity can beaccomplished using beamforming techniques.

All examples and features mentioned below can be combined in anytechnically possible way.

In one aspect, an audio system includes a loudspeaker configured tocreate an audio output, a sensor configured to detect at least thepresence of at least one person at a position relative to theloudspeaker, and a processor configured to cause the loudspeaker toalter the audio output based on the position of the at least one personrelative to the loudspeaker. Altering of the audio output includesadjusting at least one of a volume, a time delay, an equalization, or aradiation pattern of the audio output.

Some examples include one of the above and/or below features, or anycombination thereof. In an example the processor is configured to causethe loudspeaker to adjust the volume and time delay of the loudspeakeraudio output based on the position of the at least one person relativeto the loudspeaker. In some examples the sensor is configured todetermine a distance of a person from the loudspeaker. In an example theprocessor is configured to cause the loudspeaker to alter its audiooutput at least in part based on the distance of the person from theloudspeaker. In an example the sensor is part of the loudspeaker. In anexample the sensor is selected from the group of sensors consisting of aLIDAR sensor, an ultra-wide band sensor, a simultaneous location andmapping (SLAM) system, a time-of-flight infrared (IR) camera, an IRmotion sensor, a SONAR sensor, a WiFi fingerprinting system, and a videocamera.

Some examples include one of the above and/or below features, or anycombination thereof. In some examples the audio system includes aplurality of loudspeakers spaced about a listening space. In an examplethe processor is configured to alter a volume of the audio outputs ofthe plurality of loudspeakers. In an example the processor is configuredto alter a time delay of the audio outputs of the plurality ofloudspeakers.

Some examples include one of the above and/or below features, or anycombination thereof. In some examples the sensor is configured todetermine a distance of the person from each of the plurality ofloudspeakers. In an example the processor is configured to cause each ofthe plurality of loudspeakers to alter their audio outputs based on thedistance of the person from that loudspeaker. In an example each of theplurality of loudspeakers comprises a proximity sensor. In an exampleeach proximity sensor is selected from the group of proximity sensorsconsisting of a LIDAR sensor, an ultra-wide band sensor, a simultaneouslocation and mapping (SLAM) system, a time-of-flight infrared (IR)camera, an IR motion sensor, a SONAR sensor, a WiFi fingerprintingsystem, and a video camera.

Some examples include one of the above and/or below features, or anycombination thereof. In some examples each loudspeaker is configured tocommunicate with at least one other loudspeaker. In an example one ofthe plurality of loudspeakers is configured to send commands to theother loudspeakers of the plurality of loudspeakers to alter the outputsof each of the other loudspeakers based on the determined location ofthe person relative to that loudspeaker. In an example the commands areconfigured to cause each loudspeaker to adjust at least one of thevolume and time delay of its audio output. In an example eachloudspeaker comprises a sensor, and each loudspeaker is configured tocommunicate with each other loudspeaker, to coordinate alterations ofthe audio outputs of the plurality of loudspeakers.

Some examples include one of the above and/or below features, or anycombination thereof. In an example the loudspeaker comprises a pluralityof audio drivers, and the processor is configured to cause the driversto alter their level and phase to change a directivity of the collectiveoutput of the plurality of audio drivers. In another example acompensation for the radiation pattern of the audio output comprises avolume compensation across a frequency range.

In another aspect an audio system includes a plurality of loudspeakersspaced about a listening space. Each loudspeaker is configured to createan audio output. There is a sensor associated with each loudspeaker.Each sensor is configured to detect the presence of at least one personat a position relative to the loudspeaker with which the sensor isassociated. A processor is configured to cause each loudspeaker to altera volume and a time delay of its audio output based on the distance ofthe at least one person relative to the loudspeaker. In an example theplurality of loudspeakers are configured to communicate, to coordinatealterations of the audio outputs of the plurality of loudspeakers.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of at least one example are discussed below withreference to the accompanying figures, which are not intended to bedrawn to scale. The figures are included to provide illustration and afurther understanding of the various aspects and examples, and areincorporated in and constitute a part of this specification, but are notintended as a definition of the limits of the inventions. In thefigures, identical or nearly identical components illustrated in variousfigures may be represented by a like reference character or numeral. Forpurposes of clarity, not every component may be labeled in every figure.In the figures:

FIG. 1 is schematic diagram of an audio system.

FIG. 2 is a schematic diagram of a loudspeaker for an audio system.

FIG. 3A is a schematic diagram of the application of gain and delay toan audio signal based on the position of the listener relative to theloudspeaker.

FIG. 3B is a schematic diagram of the application of a filter tocompensate for off-axis frequency response.

FIG. 4A is a plot of loudspeaker output at the location of a listener infront of the speaker (in dB) vs. frequency, and FIG. 4B is a plot ofcompensation that can be applied to the loudspeaker to return thespeaker output to nominal at the listener’s location.

DETAILED DESCRIPTION

Listeners generally prefer to hear all of multiple loudspeakers(speakers) in a room or other listening area equally anywhere in theroom. This phenomenon is sometimes known as “immersive audio,” which inaddition to its ordinary meaning also means for the purpose of thisdisclosure more evenly balanced and/or more evenly distributed soundacross the space of an environment (e.g., a room). The immersive audioexperience is illusive unless the speakers have been carefullypositioned or highly directional acoustics are used, and even thenimmersion is typically limited to a predefined location in the listeningarea.

Immersive audio can be accomplished by controlling at least the output(volume) and time delay of multiple speakers based on the position ofthe listener relative to the speakers, such that the listener is able tohear each speaker regardless of position in the listening area and thesound from the multiple speakers arrives approximately simultaneously atthe listener regardless of listener’s position in the listening area.Other audio output parameters that can be controlled include theequalization, and the radiation pattern. In an example the control ofthe equalization involves a treble boost when the listener is off-axisof a speaker that is directional at high frequencies.

Examples of the systems, methods and apparatuses discussed herein arenot limited in application to the details of construction and thearrangement of components set forth in the following description orillustrated in the accompanying drawings. The systems, methods andapparatuses are capable of implementation in other examples and of beingpracticed or of being carried out in various ways. Examples of specificimplementations are provided herein for illustrative purposes only andare not intended to be limiting. In particular, functions, components,elements, and features discussed in connection with any one or moreexamples are not intended to be excluded from a similar role in anyother examples.

Examples disclosed herein may be combined with other examples in anymanner consistent with at least one of the principles disclosed herein,and references to “an example,” “some examples,” “an alternate example,”“various examples,” “one example” or the like are not necessarilymutually exclusive and are intended to indicate that a particularfeature, structure, or characteristic described may be included in atleast one example. The appearances of such terms herein are notnecessarily all referring to the same example.

Also, the phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. Any references toexamples, components, elements, acts, or functions of the computerprogram products, systems and methods herein referred to in the singularmay also embrace embodiments including a plurality, and any referencesin plural to any example, component, element, act, or function hereinmay also embrace examples including only a singularity. Accordingly,references in the singular or plural form are not intended to limit thepresently disclosed systems or methods, their components, acts, orelements. The use herein of “including,” “comprising,” “having,”“containing,” “involving,” and variations thereof is meant to encompassthe items listed thereafter and equivalents thereof as well asadditional items. References to “or” may be construed as inclusive sothat any terms described using “or” may indicate any of a single, morethan one, and all of the described terms.

In some examples an audio system includes a loudspeaker or multiplespeakers, and a processor that is configured to cause the loudspeakersto alter their audio outputs based on the position of a listenerrelative to the loudspeaker. The processor can be configured to causethe loudspeaker to alter a volume and/or the time delay of the speakerbased on the position of the listener relative to the speaker. In someexamples the position of the user is determined by a proximity sensor oranother sensor that is configured to determine a distance and/or theangular position of the person relative to the loudspeaker. In anexample the proximity sensor is part of the loudspeaker, or it can be aseparate device or system that communicates with the speaker. In someexamples one speaker is the master device that is configured to commandthe loudspeakers to alter their audio outputs at least in part based onthe distance of the person from the loudspeaker. In some examples theprocessor is configured to cause the loudspeaker to alter at least oneof a spectrum and a radiation pattern of the loudspeaker audio output.In an example there are a number of audio drivers in a housing and theprocessor is configured to cause the drivers to alter their level andphase as a function of frequency, to change a directivity of thecollective output of the drivers.

FIG. 1 illustrates room 10 in which are located separate speakers 14,16, and 18, each of which is at a different location from (i.e.,distance from and/or angle from) listener 12. In order to provide tolistener 12 immersive audio played over speakers 14, 16, and 18, thevolume of sound from each speaker, and the time of arrival of the soundfrom each speaker, should be approximately the same at the location oflistener 12.

FIG. 2 illustrates system 20 that includes speaker 22. Speaker 22includes audio driver 24 that is arranged such that its primarydirection of maximum sound radiation at most or all frequencies is fromits “front” 25. In some examples driver 24 is considered to be anomni-directional driver, although that is not a limitation of thedisclosure. The direction of the front of driver 24 will depend on theplacement of speaker 22 in the room, which is not under control of thespeaker manufacturer. Portable speakers can be placed almost anywhere ina room. Other speakers may be mounted in the ceiling. Stereo speakersare often placed spaced apart and facing an ideal listening location. Itshould be noted that speaker 22 can include more than one driver, asindicted by second driver 26. In some examples multiple drivers areuseful in situations where drivers are beamformed, as further explainedelsewhere herein.

Speaker 22 also includes proximity sensor 32 that is configured to sensethe presence of a person in a sensing area, as indicated by arrow 33. Insome examples sensor 32 is configured to detect one or more of thepresence of a person, the distance to a person, and the angle of aperson to proximity sensor 32. Proximity sensor 32 uses any now-known orfuture-developed sensing technology, including but not limited to aLIDAR-based sensor, an ultra-wide band sensor, a simultaneous locationand mapping (SLAM) system, a time-of-flight infrared (IR) camera, an IRmotion sensor, a SONAR sensor, a WiFi fingerprinting system, and a videocamera (such as those used in some gaming systems). The informationdetermined by proximity sensor 32 is provided to processor 30.Additionally or alternatively, one or both of external listener sensingdevices 40 and 42 are used to detect the presence of and/or position ofand/or angle of a person relative to the particular sensor. Sensor 40 isan external proximity sensor that is separate from speaker 22. Sensor 42is an external location tracking sensor that is separate from speaker22. Sensors 40 and/or 42, when used, are enabled to communicate withprocessor 30 either via hard wiring or wirelessly through wirelesscommunication function 34, such as by Bluetooth or WiFi.

Processor 30 is thus provided with information that is used to establishthe presence of a person in the vicinity of speaker 22. In some examplesthis information includes the distance of the person from the speaker.In some examples this information includes the angle of the person fromthe speaker, for example whether the person is in front of, to the sideof, or behind the speaker. Processor 30 uses this presence/locationinformation to alter the audio signals provided to at least driver 24,to better accomplish immersive audio to the person. In some examplesprocessor 30 provides immersive audio by altering one or more of thevolume of driver 24, the time delay of driver 24, the equalization ofdriver 24, and the radiation pattern of driver 24.

In some examples one speaker is the master device that is configured tocommand the loudspeakers to alter their audio outputs at least in partbased on the distance of the person from the loudspeaker. Coordinatedcontrol of multiple speakers is especially useful when there aremultiple speakers in a listening space that are all playing the samesound, or sounds that are meant to be heard together such as with astereo pair of speakers or a surround sound setup that can have multiplecoordinated speakers. For example, wireless communications function 34of speaker 22 can be configured to communicate with one or more otherspeakers. The presence of/location of a listener relative to eachspeaker (such as illustrated in FIG. 1 ) can be determined by sensorsthat are part of each speaker and/or are separate, such as sensors 40and 42. Any or all of such sensors can communicate with master processor30, such as through wireless communications function 34. Processor 30can be configured to process the listener’s location information andcalculate and send commands to the other speakers via wirelesscommunications 34 to alter their outputs based on the determinedlocation of the person relative to that particular loudspeaker. In someexamples these commands are configured to cause each loudspeaker toadjust one or both of the volume and time delay of its audio output. Agoal of this control of multiple speakers in a listening space is tocreate a more immersive sound field for the listener in which the volumeof the sound from the multiple speakers is more balanced than it wouldbe without the control, and these sounds reach the listener’s ears atabout the same time.

In examples in which only one speaker is involved, the speaker couldknow whether or not a person is standing directly proximate to thespeaker, such as directly under it (or within X distance of beingdirectly proximate to it, such as within 0-1 meters). This could bedetected with a simple proximity sensor, and that proximity sensor mayonly give a binary reading of “person detected” or “person notdetected.” The audio output could then be adjusted accordingly, such asreducing volume if a person is detected and increasing volume if not.

In examples of a more complex scenario, the position of one or morepeople in a given environment is tracked, and the audio output ofmultiple speakers in the given environment is adjusted accordingly, tomaintain a better multi-channel image (e.g., a better stereo image).This could be achieved by adjusting the time alignment, level,equalization, radiation pattern, and/or channel of one or more of themultiple speakers. By way of example, if two speakers were being used toprovide stereo output where one speaker outputs the left channel and theother outputs the right channel, then as the system uses one or moresensors (e.g., one or more proximity sensors, cameras, LIDAR systems,etc.) to detect that a user is moving or has moved closer to one of thetwo speakers, that closer speaker could at least one of i) decreasevolume, ii) increase playback delay, iii) adjust the equalization (e.g.,decrease treble to reduce the higher frequencies as the user is closer),iv) adjust the radiation pattern (e.g., to decrease directivity towardthe user), or v) adjust the channel output (e.g., mixing in some centercontent to help provide some of the other channel output from thatcloser speaker). The farther speaker could also or alternatively performthe opposite, i.e., adjust the audio output in at least one of thefollowing manners: i) increase volume, ii) decrease playback delay, iii)adjust the equalization (e.g., increase treble to help the higherfrequencies better reach the user), iv) adjust the radiation pattern(e.g., to increase directivity toward the user), or v) adjust thechannel output (e.g., reduce the amount of center channel that is mixedinto the output, assuming some was mixed in in the first place, toincrease its own stereo channel output).

FIG. 3A illustrates exemplary gain and delay control 50 as accomplishedby properly programmed processor 30, FIG. 2 . The speaker position 56and the listener position 54 are provided to gain and delay calculation52. In some examples the absolute locations of the speaker(s) and/or theabsolute locations of the listener(s) is determined. For example, GPS orcameras could be used to obtain the absolute locations of speakersand/or people. In some examples the speaker position is unknown and thelistener position is determined relative to the speaker (e.g., a personis within 1 meter of a speaker), in which case there would be no input56, and input 54 would be the distance of the listener rather than theposition of the listener. The calculated gain 58, along with the nominalinput audio signals 62, are provided to multiplication function 60. Theresulting revised gain 68, along with the calculated time delay 64, areprovided to audio signal delay function 66, with its outputted audiosignals 70 (which have an appropriately adjusted gain and/or time delay)provided to the audio driver(s).

To illustrate gain and delay calculation: The distance r from knownspeaker position (x,y,z) and listener position (x,y,z) can be calculatedas:

$r\, = \,\sqrt{( {x_{spkr}\, - \, x_{listener}} )^{2}\, + \,( {y_{spkr\,}\, - \, y_{listener}} )^{2}\, + \,( {z_{spkr\,}\, - \, z_{listener}} )^{2}}$

In some examples gain (G) is then calculated relative to a nominaldistance r_(nominal) where the gain is defined to be 1 at the nominaldistance.

$G\, = \,\,\frac{r}{r_{nom inal}}$

In some examples a maximum gain Gmax and a minimum gain Gmin aredefined, and if the calculated gain exceeds Gmax it is forced to Gmax,or if the gain goes below Gmin then it is forced to Gmin.

In some examples delay is calculated as follows. Start with a nominaldelay d_(nominal). Delay din samples is calculated from:

$d\,\, = \,\, d_{nominal}\, - \,\frac{r\, - \, r_{nominal}}{c}\, f_{s}$

where r and rnominal are as above, c is the speed of sound in air (343m/s), and fs is the sample rate. The delay goes down as the listenergets further away from the speaker and goes up when the listener getscloser to the speaker. This delay plus the acoustic propagation delayfrom the speaker (what the listener experiences) should equald_(nominal). The nominal delay needs to be there because the delay can’tbe less than zero when the listener moves far away from the speaker.

The output of many loudspeakers, including typical omni-directionalspeakers, becomes more directional at higher frequencies. In such casesthe speaker’s volume can drop off with frequency to the side and back ofthe speaker, as compared to in front of the speaker. The present systemcan be configured to compensate for this off-axis frequency response. Inan example illustrated in FIG. 3B, system 70 compensates for bothlistener distance 73 and the angle 78 of the listener to the speaker.Gain and delay calculation 74 calculates a gain that is provided tosumming function 76 along with input audio 75, and also calculates delay74 that is provided to delay function 77 along with the output ofsumming function 76. Listener angle 78 is compensated for using filtercoefficient generator 79 that has its output provided to audiocompensation filter 80, which is also inputted with the output offunction 77. Compensated audio output 81 is proved to the speaker (notshown). In some examples the listener angle compensation is based on theaverage response of the speaker at 360 degrees around the speaker. Thespeaker output volume can be altered based on the listener’s angle tothe speaker, to produce an output that is calculated to produce anominal response at the user’s position. As an example, FIG. 4Aillustrates curve 84, which is a response with frequency of a speaker ata position directly in front of the speaker, as compared to the averageresponse of the speaker at all angles relative to the speaker. Thedirectionality at higher frequencies is illustrated by the responseincreasing well above nominal, particularly at frequencies greater thanabout 2 kHz. FIG. 4B illustrates curve 86, which is a compensation thatcan be accomplished by the processor, to provide a nominal response atthe particular position (in front of the speaker) across the frequencyrange. Thus, since at higher frequencies the response of the speakerincreases as compared to at positions to the side and behind thespeaker, the processor would need to create a response(FIG. 4B) that isthe inverse of the FIG. 4A curve, in which the volume is decreased withfrequency as shown. In contrast, at 180 degrees around the speaker(i.e., at the back), the response drops off with frequency and thecompensation thus would increase with frequency.

Phased-array speaker systems include multiple audio drivers arrangedsuch that their outputs can be beamformed, as is known in the art.Beamforming can be used to steer the main sound beam or lobe in adesired direction. Beamforming may involve changing the volume and phaseof the speakers as a function of frequency to develop desireddirectionality. In some examples herein the directivity of the mainsound lobe of a multiple audio driver loudspeaker is adjusted based onthe listener’s position. For example, in a phased array speaker systemwhen the listener’s angular position relative to the loudspeaker isknown, the drivers can be beamformed to direct the sound at the positionof the listener.

Elements of figures are shown and described as discrete elements in ablock diagram. These may be implemented as one or more of analogcircuitry or digital circuitry. Alternatively, or additionally, they maybe implemented with one or more microprocessors executing softwareinstructions. The software instructions can include digital signalprocessing instructions. Operations may be performed by analog circuitryor by a microprocessor executing software that performs the equivalentof the analog operation. Signal lines may be implemented as discreteanalog or digital signal lines, as a discrete digital signal line withappropriate signal processing that is able to process separate signals,and/or as elements of a wireless communication system.

When processes are represented or implied in the block diagram, thesteps may be performed by one element or a plurality of elements. Thesteps may be performed together or at different times. The elements thatperform the activities may be physically the same or proximate oneanother, or may be physically separate. One element may perform theactions of more than one block. Audio signals may be encoded or not, andmay be transmitted in either digital or analog form. Conventional audiosignal processing equipment and operations are in some cases omittedfrom the drawing.

Examples of the systems and methods described herein comprise computercomponents and computer-implemented steps that will be apparent to thoseskilled in the art. For example, it should be understood by one of skillin the art that the computer-implemented steps may be stored ascomputer-executable instructions on a computer-readable medium such as,for example, hard disks, optical disks, Flash ROMS, nonvolatile ROM, andRAM. Furthermore, it should be understood by one of skill in the artthat the computer-executable instructions may be executed on a varietyof processors such as, for example, microprocessors, digital signalprocessors, gate arrays, etc. For ease of exposition, not every step orelement of the systems and methods described above is described hereinas part of a computer system, but those skilled in the art willrecognize that each step or element may have a corresponding computersystem or software component. Such computer system and/or softwarecomponents are therefore enabled by describing their corresponding stepsor elements (that is, their functionality), and are within the scope ofthe disclosure.

Functions, methods, and/or components of the methods and systemsdisclosed herein according to various aspects and examples may beimplemented or carried out in a digital signal processor (DSP) and/orother circuitry, analog or digital, suitable for performing signalprocessing and other functions in accord with the aspects and examplesdisclosed herein. Additionally or alternatively, a microprocessor, alogic controller, logic circuits, field programmable gate array(s)(FPGA), application-specific integrated circuits) (ASIC), generalcomputing processor(s), micro- controller(s), and the like, or anycombination of these, may be suitable, and may include analog or digitalcircuit components and/or other components with respect to anyparticular implementation.

Functions and components disclosed herein may operate in the digitaldomain, the analog domain, or a combination of the two, and certainexamples include analog-to-digital converters) (ADC) and/ordigital-to-analog converter(s) (DAC) where appropriate, despite the lackof illustration of ADC’s or DAC’s in the various figures. Further,functions and components disclosed herein may operate in a time domain,a frequency domain, or a combination of the two, and certain examplesinclude various forms of Fourier or similar analysis, synthesis, and/ortransforms to accommodate processing in the various domains.

Any suitable hardware and/or software, including firmware and the like,may be configured to carry out or implement components of the aspectsand examples disclosed herein, and various implementations of aspectsand examples may include components and/or functionality in addition tothose disclosed. Various implementations may include stored instructionsfor a digital signal processor and/or other circuitry to enable thecircuitry, at least in part, to perform the functions described herein.

Having described above several aspects of at least one example, it is tobe appreciated various alterations, modifications, and improvements willreadily occur to those skilled in the art. Such alterations,modifications, and improvements are intended to be part of thisdisclosure and are intended to be within the scope of the invention.Accordingly, the foregoing description and drawings are by way ofexample only, and the scope of the invention should be determined fromproper construction of the appended claims, and their equivalents.

1. An audio system, comprising: a loudspeaker configured to create anaudio output that is characterized by a nominal volume output thatvaries at different frequencies across a loudspeaker output frequencyrange; a sensor configured to detect at least the angle of at least oneperson at relative to the loudspeaker; and a processor, responsive tothe sensor, configured to cause the loudspeaker to vary the volume ofthe audio output of the loudspeaker relative to the nominal volumeoutput based on the position of the at least one person relative to theloudspeaker, wherein the variation is at least in part based on theoutput frequencies across the output frequency range.
 2. The audiosystem of claim 1, wherein the processor is further configured to causethe loudspeaker to adjust the time delay of the loudspeaker audio outputbased on the position of the at least one person relative to theloudspeaker.
 3. The audio system of claim 1, wherein the sensor isfurther configured to determine at least one of a distance of a personfrom the loudspeaker or a location of a person.
 4. The audio system ofclaim 3, wherein the processor is further configured to cause theloudspeaker to alter its audio output at least in part based on at leastone of the distance of the person from the loudspeaker or the locationof the person.
 5. The audio system of claim 1, wherein the sensor ispart of the loudspeaker.
 6. The audio system of claim 1, wherein thesensor is selected from the group of sensors consisting of a LIDARsensor, an ultra-wide band sensor, a simultaneous location and mapping(SLAM) system, a time-of-flight infrared (IR) camera, an IR motionsensor, a SONAR sensor, a WiFi fingerprinting system, and a videocamera.
 7. The audio system of claim 1, comprising a plurality ofloudspeakers spaced about a listening space.
 8. The audio system ofclaim 7, wherein the processor is further configured to vary the volumeof the audio outputs of each of the plurality of loudspeakers.
 9. Theaudio system of claim 7, wherein the processor is further configured toalter a time delay of the audio outputs of each of the plurality ofloudspeakers.
 10. The audio system of claim 7, wherein the sensor isconfigured to determine a distance of the person from each of theplurality of loudspeakers.
 11. The audio system of claim 10, wherein theprocessor is configured to cause each of the plurality of loudspeakersto alter their audio outputs based on the distance of the person fromthat loudspeaker.
 12. The audio system of claim 10, wherein each of theplurality of loudspeakers comprises a proximity sensor.
 13. The audiosystem of claim 12, wherein each proximity sensor is selected from thegroup of proximity sensors consisting of a LIDAR sensor, an ultra-wideband sensor, a simultaneous location and mapping (SLAM) system, atime-of-flight infrared (IR) camera, an IR motion sensor, a SONARsensor, a WiFi fingerprinting system, and a video camera.
 14. The audiosystem of claim 7, wherein each loudspeaker is configured to communicatewith at least one other loudspeaker.
 15. The audio system of claim 14,wherein one of the plurality of loudspeakers is configured to sendcommands to the other loudspeakers of the plurality of loudspeakers toalter the outputs of each of the other loudspeakers based at least onthe determined angle of the person relative to that loudspeaker.
 16. Theaudio system of claim 15, wherein the commands are configured to causeeach loudspeaker to adjust the volume and time delay of its audiooutput.
 17. The audio system of claim 7, wherein each loudspeakercomprises a sensor and wherein each loudspeaker is configured tocommunicate with each other loudspeaker, to coordinate alterations ofthe audio outputs of the plurality of loudspeakers.
 18. The audio systemof claim 1, wherein the loudspeaker comprises a plurality of audiodrivers, and wherein the processor is further configured to cause thedrivers to alter their level and phase to change a directivity of thecollective output of the plurality of audio drivers.
 19. (canceled) 20.An audio system, comprising: a plurality of loudspeakers spaced about alistening space, wherein each loudspeaker is configured to create anaudio output that is characterized by a nominal volume output thatvaries at different frequencies across a loudspeaker output frequencyrange; a sensor associated with each loudspeaker, wherein each sensor isconfigured to detect at least the presencedistance and angle of at leastone person at a position relative to the loudspeaker with which thesensor is associated; and a processor configured to cause eachloudspeaker to alter a volume and a time delay of its audio output basedon the distance and angle of the at least one person relative to theloudspeaker, wherein the volume variation is relative to the nominalvolume output of the respective loudspeaker and is at least in partbased on the output frequencies of the respective loudspeaker across itsoutput frequency range.
 21. The audio system of claim 20, wherein theplurality of loudspeakers are configured to communicate, to coordinatealterations of the audio outputs of the plurality of loudspeakers. 22.The audio system of claim 1, wherein the volume variation of theloudspeaker is the inverse of its nominal output.